Thank you to UBC Botanical Garden horticulturist Jackie Chambers for today’s photographs and write-up, much appreciated!
A fine example of Trachystemon orientalis can be found in the David C. Lam Asian Garden here at UBC. The coarse-textured, heart-shaped leaves are bright green and reach 25-30cm long. However, it is the dainty blue flowers, currently in bloom, that are the most striking feature of this perennial groundcover.
The flowers are held on hairy, purple flower stalks of 15-30cm in height. Flower stalks emerge in early spring (March-April) before the leaves have reached full size. Individual flowers are about 1cm in diameter, and are hermaphroditic – meaning they have both staminate (pollen producing) and carpellate (ovule producing) structures (additional photographs). Stiff hairs and blue flowers are typical features of members of Boraginaceae.
Trachystemon is derived from the Greek trachys, meaning rough, and stemon, a stamen. The species name orientalis means eastern or from the orient, and is a reference to the native distribution of this species. Trachystemon orientalis is endemic to southeastern Europe and western Asia.
In Turkey, the plant is eaten as a vegetable, and has the common name aci hodan. The flowers, stems, young leaves and rhizome may all be cooked and eaten (see the entry on Trachystemon orientalis on Plants for a Future database).
English common names include Abraham-Isaac-Jacob, and Eastern or Oriental borage. Despite being native to Bulgaria, Turkey, and Georgia, Trachystemon orientalis has naturalized throughout the UK. It was first introduced as an ornamental, but records indicate established escapee populations in some areas of England date back to 1868. Here’s a more recent distribution map of Trachystemon orientalis populations in the UK.
From a horticulturist perspective, this plant is an extremely useful groundcover; while it prefers partly shaded woodland locations, it can tolerate full sun to shade, and a range of soil conditions. It even performs well in dry shade which is always a challenge for gardeners.